#define  _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
#include<assert.h>
#include<string.h>
char* my_strcpy(char* str1, char* str2)
{
	assert(str1 && str2);
	char* dest = str1;
	while (*dest++ = *str2++)
	{
		;
	}
	return str1;
}
int main()
{
	char arr1[20] = "abc";
	char arr2[] = "cdef";
	strcpy(arr1, arr2);
	printf("%s\n", arr1);
	return 0;
}